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  1. Mar 02, 2022
    • Su Yue's avatar
      btrfs: tree-checker: check item_size for inode_item · 5c967dd0
      Su Yue authored
      commit 0c982944 upstream.
      
      while mounting the crafted image, out-of-bounds access happens:
      
        [350.429619] UBSAN: array-index-out-of-bounds in fs/btrfs/struct-funcs.c:161:1
        [350.429636] index 1048096 is out of range for type 'page *[16]'
        [350.429650] CPU: 0 PID: 9 Comm: kworker/u8:1 Not tainted 5.16.0-rc4 #1
        [350.429652] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
        [350.429653] Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs]
        [350.429772] Call Trace:
        [350.429774]  <TASK>
        [350.429776]  dump_stack_lvl+0x47/0x5c
        [350.429780]  ubsan_epilogue+0x5/0x50
        [350.429786]  __ubsan_handle_out_of_bounds+0x66/0x70
        [350.429791]  btrfs_get_16+0xfd/0x120 [btrfs]
        [350.429832]  check_leaf+0x754/0x1a40 [btrfs]
        [350.429874]  ? filemap_read+0x34a/0x390
        [350.429878]  ? load_balance+0x175/0xfc0
        [350.429881]  validate_extent_buffer+0x244/0x310 [btrfs]
        [350.429911]  btrfs_validate_metadata_buffer+0xf8/0x100 [btrfs]
        [350.429935]  end_bio_extent_readpage+0x3af/0x850 [btrfs]
        [350.429969]  ? newidle_balance+0x259/0x480
        [350.429972]  end_workqueue_fn+0x29/0x40 [btrfs]
        [350.429995]  btrfs_work_helper+0x71/0x330 [btrfs]
        [350.430030]  ? __schedule+0x2fb/0xa40
        [350.430033]  process_one_work+0x1f6/0x400
        [350.430035]  ? process_one_work+0x400/0x400
        [350.430036]  worker_thread+0x2d/0x3d0
        [350.430037]  ? process_one_work+0x400/0x400
        [350.430038]  kthread+0x165/0x190
        [350.430041]  ? set_kthread_struct+0x40/0x40
        [350.430043]  ret_from_fork+0x1f/0x30
        [350.430047]  </TASK>
        [350.430077] BTRFS warning (device loop0): bad eb member start: ptr 0xffe20f4e start 20975616 member offset 4293005178 size 2
      
      check_leaf() is checking the leaf:
      
        corrupt leaf: root=4 block=29396992 slot=1, bad key order, prev (16140901064495857664 1 0) current (1 204 12582912)
        leaf 29396992 items 6 free space 3565 generation 6 owner DEV_TREE
        leaf 29396992 flags 0x1(WRITTEN) backref revision 1
        fs uuid a62e00e8-e94e-4200-8217-12444de93c2e
        chunk uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8
      	  item 0 key (16140901064495857664 INODE_ITEM 0) itemoff 3955 itemsize 40
      		  generation 0 transid 0 size 0 nbytes 17592186044416
      		  block group 0 mode 52667 links 33 uid 0 gid 2104132511 rdev 94223634821136
      		  sequence 100305 flags 0x2409000(none)
      		  atime 0.0 (1970-01-01 08:00:00)
      		  ctime 2973280098083405823.4294967295 (-269783007-01-01 21:37:03)
      		  mtime 18446744071572723616.4026825121 (1902-04-16 12:40:00)
      		  otime 9249929404488876031.4294967295 (622322949-04-16 04:25:58)
      	  item 1 key (1 DEV_EXTENT 12582912) itemoff 3907 itemsize 48
      		  dev extent chunk_tree 3
      		  chunk_objectid 256 chunk_offset 12582912 length 8388608
      		  chunk_tree_uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8
      
      The corrupted leaf of device tree has an inode item. The leaf passed
      checksum and others checks in validate_extent_buffer until check_leaf_item().
      Because of the key type BTRFS_INODE_ITEM, check_inode_item() is called even we
      are in the device tree. Since the
      item offset + sizeof(struct btrfs_inode_item) > eb->len, out-of-bounds access
      is triggered.
      
      The item end vs leaf boundary check has been done before
      check_leaf_item(), so fix it by checking item size in check_inode_item()
      before access of the inode item in extent buffer.
      
      Other check functions except check_dev_item() in check_leaf_item()
      have their item size checks.
      The commit for check_dev_item() is followed.
      
      No regression observed during running fstests.
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215299
      
      
      CC: stable@vger.kernel.org # 5.10+
      CC: Wenqing Liu <wenqingliu0120@gmail.com>
      Signed-off-by: default avatarSu Yue <l@damenly.su>
      Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5c967dd0
    • Zhang Qiao's avatar
      cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug · fcec42dd
      Zhang Qiao authored
      commit 05c7b7a9 upstream.
      
      As previously discussed(https://lkml.org/lkml/2022/1/20/51),
      cpuset_attach() is affected with similar cpu hotplug race,
      as follow scenario:
      
           cpuset_attach()				cpu hotplug
          ---------------------------            ----------------------
          down_write(cpuset_rwsem)
          guarantee_online_cpus() // (load cpus_attach)
      					sched_cpu_deactivate
      					  set_cpu_active()
      					  // will change cpu_active_mask
          set_cpus_allowed_ptr(cpus_attach)
            __set_cpus_allowed_ptr_locked()
             // (if the intersection of cpus_attach and
               cpu_active_mask is empty, will return -EINVAL)
          up_write(cpuset_rwsem)
      
      To avoid races such as described above, protect cpuset_attach() call
      with cpu_hotplug_lock.
      
      Fixes: be367d09
      
       ("cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time")
      Cc: stable@vger.kernel.org # v2.6.32+
      Reported-by: default avatarZhao Gongyi <zhaogongyi@huawei.com>
      Signed-off-by: default avatarZhang Qiao <zhangqiao22@huawei.com>
      Acked-by: default avatarWaiman Long <longman@redhat.com>
      Reviewed-by: default avatarMichal Koutný <mkoutny@suse.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fcec42dd
  2. Feb 23, 2022